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ep93xx: Use ioremap for backlight driver

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The ep93xx backlight driver uses a single register within the
framebuffer's register space. Currently the backlight driver uses a
static IO mapping for the register since the memory cannot be
requested by both drivers.

Convert the static mapping to use ioremap so that we can remove the
dependency on mach/hardware.h. To do so, we need remove the
request_mem_region from both the backlight and framebuffer drivers,
since whichever driver is loaded second will fail with -EBUSY
otherwise.

A proper fix is still required, and a FIXME comment has been added to
both drivers.

Signed-off-by: Ryan Mallon <rmallon@gmail.com>
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Cc: Mika Westerberg <mika.westerberg@iki.fi>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
This commit is contained in:
Ryan Mallon 2012-01-22 20:31:32 +11:00
parent 2ae18b471d
commit 0fd1958050
3 changed files with 33 additions and 20 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
arch/arm/mach-ep93xx/core.c
View File

@ -682,9 +682,19 @@ static struct platform_device ep93xx_fb_device = {
.resource = ep93xx_fb_resource,
};
/* The backlight use a single register in the framebuffer's register space */
#define EP93XX_RASTER_REG_BRIGHTNESS 0x20
static struct resource ep93xx_bl_resources[] = {
DEFINE_RES_MEM(EP93XX_RASTER_PHYS_BASE +
EP93XX_RASTER_REG_BRIGHTNESS, 0x04),
};
static struct platform_device ep93xx_bl_device = {
.name = "ep93xx-bl",
.id = -1,
.num_resources = ARRAY_SIZE(ep93xx_bl_resources),
.resource = ep93xx_bl_resources,
};
/**

25
drivers/video/backlight/ep93xx_bl.c
View File

@ -17,11 +17,6 @@
#include <linux/fb.h>
#include <linux/backlight.h>
#include <mach/hardware.h>
#define EP93XX_RASTER_REG(x) (EP93XX_RASTER_BASE + (x))
#define EP93XX_RASTER_BRIGHTNESS EP93XX_RASTER_REG(0x20)
#define EP93XX_MAX_COUNT 255
#define EP93XX_MAX_BRIGHT 255
#define EP93XX_DEF_BRIGHT 128
@ -35,7 +30,7 @@ static int ep93xxbl_set(struct backlight_device *bl, int brightness)
{
struct ep93xxbl *ep93xxbl = bl_get_data(bl);
__raw_writel((brightness << 8) | EP93XX_MAX_COUNT, ep93xxbl->mmio);
writel((brightness << 8) | EP93XX_MAX_COUNT, ep93xxbl->mmio);
ep93xxbl->brightness = brightness;
@ -70,21 +65,29 @@ static int __init ep93xxbl_probe(struct platform_device *dev)
struct ep93xxbl *ep93xxbl;
struct backlight_device *bl;
struct backlight_properties props;
struct resource *res;
ep93xxbl = devm_kzalloc(&dev->dev, sizeof(*ep93xxbl), GFP_KERNEL);
if (!ep93xxbl)
return -ENOMEM;
res = platform_get_resource(dev, IORESOURCE_MEM, 0);
if (!res)
return -ENXIO;
/*
* This register is located in the range already ioremap'ed by
* the framebuffer driver. A MFD driver seems a bit of overkill
* to handle this so use the static I/O mapping; this address
* is already virtual.
* FIXME - We don't do a request_mem_region here because we are
* sharing the register space with the framebuffer driver (see
* drivers/video/ep93xx-fb.c) and doing so will cause the second
* loaded driver to return -EBUSY.
*
* NOTE: No locking is required; the framebuffer does not touch
* this register.
*/
ep93xxbl->mmio = EP93XX_RASTER_BRIGHTNESS;
ep93xxbl->mmio = devm_ioremap(&dev->dev, res->start,
resource_size(res));
if (!ep93xxbl->mmio)
return -ENXIO;
memset(&props, 0, sizeof(struct backlight_properties));
props.type = BACKLIGHT_RAW;

18
drivers/video/ep93xx-fb.c
View File

@ -519,12 +519,15 @@ static int __devinit ep93xxfb_probe(struct platform_device *pdev)
goto failed;
}
res = request_mem_region(res->start, resource_size(res), pdev->name);
if (!res) {
err = -EBUSY;
goto failed;
}
/*
* FIXME - We don't do a request_mem_region here because we are
* sharing the register space with the backlight driver (see
* drivers/video/backlight/ep93xx_bl.c) and doing so will cause
* the second loaded driver to return -EBUSY.
*
* NOTE: No locking is required; the backlight does not touch
* any of the framebuffer registers.
*/
fbi->res = res;
fbi->mmio_base = ioremap(res->start, resource_size(res));
if (!fbi->mmio_base) {
@ -586,8 +589,6 @@ failed:
clk_put(fbi->clk);
if (fbi->mmio_base)
iounmap(fbi->mmio_base);
if (fbi->res)
release_mem_region(fbi->res->start, resource_size(fbi->res));
ep93xxfb_dealloc_videomem(info);
if (&info->cmap)
fb_dealloc_cmap(&info->cmap);
@ -608,7 +609,6 @@ static int __devexit ep93xxfb_remove(struct platform_device *pdev)
clk_disable(fbi->clk);
clk_put(fbi->clk);
iounmap(fbi->mmio_base);
release_mem_region(fbi->res->start, resource_size(fbi->res));
ep93xxfb_dealloc_videomem(info);
fb_dealloc_cmap(&info->cmap);